Parking cooler

ABSTRACT

A parking cooler which is capable of battery powered operation during engine off operation. The parking cooler or air conditioning system may vary in cooling capacities to maximize cooling or maximize battery life. The parking cooler includes one or more condensers and a housing to accommodate such variation of cooling capacity.

CROSS-REFERENCE

Cross-reference is made to U.S. Design patent application Ser. No.29/552,019, titled “Air Shroud Assembly,” filed on Jan. 19, 2016 and isexpressly incorporated herein by reference.

CLAIM TO PRIORITY

This divisional patent application claims priority to and benefit of,under 35 U.S.C. § 121, U.S. patent application Ser. No. 15/407,709,filed Jan. 17, 2017, titled “Parking Cooler”, which claims priority,under U.S.C. § 119(e), U.S. Provisional Patent Application Ser. No.62/280,352, filed Jan. 19, 2016, titled “Parking Cooler”, all of whichis incorporated by reference herein.

BACKGROUND Field of the Invention

Present embodiments pertain to a parking cooler for over-the-roadvehicles. More particularly, the present embodiments pertain to aparking cooler having battery powered air conditioning using a variablespeed compressor which varies operating conditions based on comparisonsbetween temperature set point and actual temperature in a cabin.

Description of the Related Art

The increasing use of over-the-road trucks for shipping has resulted ina need for trucks to have air conditioning systems that are moreenvironmentally friendly and which provide adequate environmentalconditioning for drivers.

In long haul trucking, regulations require rest periods for driverswhich have logged some maximum number of consecutive driving hours, ordriving hours in a 24-hour period. When the limit is met, the driversare required to pull off the road and rest for a preselected number ofhours. Due to the requirement to pull off the road, the driver may notbe able to stop at a location having shore power. Therefore, in priorart systems, trucks were required to run the engines to operate the airconditioning system and provide suitable conditions to acquire rest.

Subsequently, environmental concerns have also required that systems bedeveloped which do not require idling of the truck in order to operatethe air conditioning. This is in reaction to desires to decrease enginepollution which has, in part, been associated with idling engines.

Thus, there is a desire to provide improved environmental conditions byreducing wasted fuel and emissions associated with solely running an airconditioning system. Further, there is a competing need to provide anair-conditioning system when the truck engine is not operating toprovide for driver comfort and rest.

Still further, with the desire to operate an air conditioning systemsolely on battery power when the truck engine is not operating, it isalso desirable to provide a system which can utilize the battery poweras efficiently as possible, to maintain desirable resting conditions forthe driver for as long as possible.

Even further, in developing systems to meet the above criteria, it isalso desirable to meet cooling capacity for various vehicles. There arevarious sizes of vehicles requiring differing cooling capacities.Accordingly, the ability to accommodate various cooling capacitieswithout requiring a large number of additional parts would be desirableboth for manufacturing and service and repair.

The information included in this Background section of thespecification, including any references cited herein and any descriptionor discussion thereof, is included for technical reference purposes onlyand is not to be regarded subject matter by which the scope of theinvention is to be bound.

SUMMARY

In view of the preceding, the present embodiments provide a parkingcooler which may be operated from battery power. Further, the systemshould have cooling capacities which may vary so as to accommodatedifferent levels of cooling desired for a truck cabin. Further, presentembodiments have features which improve the life of the batteries whenthe vehicle engine is not operating.

According to some embodiments, a mobile air conditioning systemcomprises a housing having an interior space for positioning of coolingmechanicals, the cooling mechanicals including at least a DC brushlessvariable speed compressor, an expansion valve, an evaporator and atleast one condenser. The interior space of the housing may be arrangedsuch that the at least one first condenser is arranged at one side ofthe interior space and a second symmetrically opposite side of theinterior space is available and capable of receiving a second condenserto increase cooling capacity of the cooling mechanicals.

Optionally, the housing is a single housing and may further comprise acontroller mounted on a printed circuit board. The mobile airconditioning system may further comprise an air distribution assemblyconnected to the housing. The air distribution assembly may have an airintake register and an air output vent. In some embodiments, the housingmay be two housings. A controller may be mounted on a printed circuitboard. The evaporator may be mounted in a first housing of the twohousings. The compressor and the at least one condenser may be mountedin a second of the two housings. An air distribution assembly may beconnected to the first housing. In some embodiments, the mobile airconditioning system may further comprise the second condenser. Thesecond condenser may have substantially the same capacity as the atleast one first condenser. The second symmetrically opposite side of theinterior space may be empty. The air conditioning system may have adifferent capacity than the second condenser. In some embodiments, thehousing may include a first housing that is adjacent to a secondhousing. Alternatively, the first housing may be spaced from the secondhousing. In either embodiment, one of said first or second housings maybe located inside of a cab of a vehicle.

In a further embodiment, a mobile air conditioning system may comprise ahousing having a plurality of cooling mechanicals including a DCbrushless variable speed compressor, an expansion valve, an evaporatorand at least one condenser, and a printed circuit board disposed withinthe housing. The printed circuit board may include a microprocessor unitand an on-board driver which drives the DC brushless variable speedcompressor, the on-board driver being in electrical communication withthe DC brushless variable speed compressor. The printed circuit boardmay also be in electrical communication with an evaporator fan and atleast one condenser fan. At least one cabin temperature and an outsidetemperature sensor may be in communication with the printed circuitboard.

Optionally, the housing being a single housing or the housing may be afirst housing and a second housing. The printed circuit board in remotecommunication with a display. The printed circuit board may receivepower from a vehicle. The printed circuit board receiving 12V DC or 24VDC power. The printed circuit board may provide a speed signal to theevaporator fan and the at least one condenser fan. The printed circuitboard may receive a tachometer feedback signal. The mobile airconditioning system may further comprise at least one communication porton the printed circuit board for communication with the at least onecondenser fan. The mobile air conditioning system may further comprise asecond condenser and second condenser fan. At least one communicationport may also in communication with the second condenser fan. The secondcondenser and the first condenser may be symmetrically arranged withinthe housing. The system may further comprise a compressor temperaturesensor in communication with the printed circuit board. The mobile airconditioning system may further comprise a battery voltage sensor incommunication with the printed circuit board.

In a further embodiment, a controller for an air conditioning system maycomprise a printed circuit board having a substrate including aplurality of electrical communication paths, a motor of a variable speedcompressor driven from said printed circuit board, the printed circuitboard determining if actuators and sensors are in electricalcommunication with the printed circuit board, a communication bus whichreceives input of a plurality of parameters from a display printedcircuit board and, wherein the plurality of parameters defining controlvalues for the actuators.

Optionally, the control values may be stored on a display printedcircuit board. The display printed circuit board may send the controlvalues to the printed circuit board. In other embodiments, the controlvalues may be stored on the printed circuit board. The printed circuitboard may receive a signal corresponding to one of the parameters from adisplay circuit board. The control values may correspond to speedsettings for the actuators. The controller may be utilized with airconditioning systems of various capacity. The controller may furthercomprise a converter which steps up voltage. The actuators may includeat least one condenser fan, an evaporation fan and the variable speedcompressor. The sensors may comprise a cabin temperature sensor, anoutside temperature sensor, and a compressor temperature sensor. Thesensors may comprise a battery voltage sensor isolated from other power.The actuators may further comprise a condensate water pump. The sensorsfurther comprise a water level sensor. The controller may furthercomprise a DC-DC converter. The parameters may include a selection of atleast one of automatic mode, economic mode and manual mode. Theparameters may further define fan speeds and compressor motor speed. Theparameters may further comprise a boost mode. In the boost mode, atleast one of the evaporator fan speed, condenser fan speed andcompressor speed may be maximized.

All of the above outlined features are to be understood as exemplaryonly and many more features and objectives of a parking air conditioningsystem or cooler may be gleaned from the disclosure herein. Therefore,no limiting interpretation of this summary is to be understood withoutfurther reading of the entire specification, claims and drawings,included herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the embodiments may be better understood, embodiments ofthe parking cooler will now be described by way of examples. Theseembodiments are not to limit the scope of the claims as otherembodiments of the parking cooler will become apparent to one havingordinary skill in the art upon reading the instant description.Non-limiting examples of the present embodiments are shown in figureswherein:

FIG. 1 is a side schematic view of one embodiment of a mobile airconditioner for parking cooling with a single housing;

FIG. 2 is a side schematic view of a second embodiment of a mobile airconditioner for parking cooling with dual housings;

FIGS. 3A-3C are further embodiments of a mobile air conditioner forparking cooling with in various configurations;

FIG. 4 is a perspective view of one embodiment of a housing which mayhouse one or more symmetrically positioned condensers;

FIG. 5 is a front view of the example housing of FIG. 4 ;

FIG. 6 is a side view of the example housing of FIG. 4 ;

FIG. 7 is a perspective view of one embodiment of the coolingmechanicals;

FIG. 8 is a perspective view of an alternate embodiment of the coolingmechanicals;

FIGS. 9A and 9B are a schematic view of various components of theparking cooler; and,

FIG. 10 depicts a flow chart of a method of using the parking cooler.

DETAILED DESCRIPTION

It is to be understood that the parking cooler is not limited in itsapplication to the details of construction and the arrangement ofcomponents set forth in the following description or illustrated in thedrawings. The embodiments are capable of other embodiments and of beingpracticed or of being carried out in various ways. Also, it is to beunderstood that the phraseology and terminology used herein is for thepurpose of description and should not be regarded as limiting. The useof “including,” “comprising,” or “having” and variations thereof hereinis meant to encompass the items listed thereafter and equivalentsthereof as well as additional items. Unless limited otherwise, the terms“connected,” “coupled,” and “mounted,” and variations thereof herein areused broadly and encompass direct and indirect connections, couplings,and mountings. In addition, the terms “connected” and “coupled” andvariations thereof are not restricted to physical or mechanicalconnections or couplings.

Referring now in detail to the drawings, wherein like numerals indicatelike elements throughout several views, there are shown in the FIGS.1-10 various embodiments of a mobile air conditioning system whichprovides parking cooling. The present embodiments may be located in onehousing or in a split-apart housing arrangement. The housing is sized tobe capable of working with various capacities of cooling mechanicals sothat vehicles of differing sizes or of varying cooling needs may besatisfied. Additionally, the air conditioning system may be batterypowered and the variable speed compressor may be driven by a driverwhich is on-board, a printed circuit board which controls the airconditioner rather than from a separate external driver, for exampleon-board the compressor. Features are provided for controlling themobile air conditioning system to prolong battery life for longer restintervals with conditioned air. Thus, the air conditioning provided bythe parking cooler is independent in operation of the engine operationstatus, for example, on or off.

Referring now to FIG. 1 , a side schematic view of a mobile airconditioning system or parking cooler 10 is shown mounted on a vehicle12, for example an over-the-road hauling truck. The truck may have a gasor diesel combustion engine 15 which is connected to a transmission fordriving one or more pairs of wheels. At a forward end of the vehicle 12is a cab or cabin 13 wherein the vehicle 12 may be driven and/or whereina driver may sleep. The cab 13 may be over the engine 15, as depicted,or the engine may be forward of the cab. Additionally, some vehicles mayfurther comprise a sleeper 19 wherein the driver or co-driver/passengermay rest.

The mobile air conditioning system 10 is shown mounted on a roof 14 ofthe vehicle 12 but may be mounted in other locations. The roof 14 of thevehicle 12 is generally shown as a flat roof or having a slight slopefrom back to front and/or side to side. However, in other embodiments,the roof may be sloped, for example up to some pre-defined limit. Suchlimitation may be in part dependent upon truck design as well asmounting configurations and capabilities of the compressor. Further, themobile air conditioning system 10 may be positioned behind a cowling(not shown), for example which are sometimes desirable to improveaerodynamics of the vehicle 12.

The mobile air conditioning system 10 may be embodied by a singlehousing system or may be embodied by two or more housings. As shown inFIG. 1 , the mobile air conditioning system 10 includes a single housing16 which houses the cooling mechanicals 11. The cooling mechanicals 11according to some embodiments may include a printed circuit board 310(FIG. 9A) and controller 300 (FIG. 9A), a compressor 40 (FIG. 7 ), oneor more condensers 44 (FIG. 7 ), an expansion valve 48 (FIG. 7 ), and anevaporator 50 (FIG. 7 ). In some embodiments, where a single housing isused, the housing 16 may extend through the vehicle roof 14 so that anair distribution assembly 20 is in flow communication with the housingand cycles air from the interior of the vehicle 12 through the housing16 back into the vehicle 12. The air distribution assembly 20 may beformed with the housing 16 or may be connected to the housing 16 andextend through the roof 14 or vehicle wall or according to anon-limiting alternative, for example may sandwich or capture the roof14 or other vehicle wall therebetween.

Referring now to FIG. 2 , a side view of an alternative configuration isdepicted. In this embodiment, the housing 116 is defined by two housings117, 119. The first housing 117 is shown mounted on the roof 14 of thevehicle 12. The second housing 119 is shown mounted on the rear of thevehicle 12. The cooling mechanicals 11 may be split between the twohousings 117, 119. The first housing 117 may be disposed on a flat orsloped roof, or may be mounted behind a cowling as described in previousembodiments. Further, the first housing 117 may have at least anevaporator and a printed circuit board with attached controller therein.An air distribution assembly 20 may be depending from the first housing117 and may be integrally formed with the first housing 117 or may beconnected to the first housing 117. The air distribution assembly 20directs cabin air to the evaporator for heat exchange or alternatively,the evaporator may extend into a portion of the air distributionassembly 20 for heat exchange therein.

In the example embodiment, the second housing 119 may have the at leastone condenser 44 (FIG. 7 ) therein and the compressor 40 (FIG. 7 ). Anexpansion valve 48 (FIG. 7 ) may be located in either of the first orthe second housings 117, 119. In some embodiments, it may be desirableto locate the expansion valve 48 near or in the housing 117, 119 havingthe evaporator. Further, the cooling mechanicals 11 located in thesecond housing 119 are in fluid communication with the coolingmechanicals 11 of the first housing 117 so that refrigerant may flowbetween. The flow path may be internal to the vehicle 12 or may beexternal to the vehicle 12.

As one skilled in the art will understand, the refrigerant is compressedby the compressor 40, then moves to the at least one condenser 44 wherethe high pressure gas is cooled by the condenser with external air. Asthis occurs, the refrigerant may change phases from a gas to a liquid atwhich time, the refrigerant next passes through an expansion valve 48and changes from a high pressure to a lower pressure fluid, for examplea liquid. The low pressure refrigerant next passes to the evaporator 50and heat is exchanged to the refrigerant from cabin air passing over theevaporator coils. The conditioned cabin air then travels back to thecabin as conditioned air for cooling and/or dehumidifying. Thisrefrigerant circuit may be used in either of the single housing 16embodiment or the multiple housing 116, 216 embodiments.

Referring now to FIG. 3A, a further side schematic view of an additionalembodiment is depicted. In this embodiment, a housing 216 is showndisposed on the rear wall of the vehicle 12. The housing 216 may be adual housing comprising an internal housing 217 and an external housing219. In this embodiment however, the dual housings 217, 219 may belocated adjacent to each other so that the two housings are not splitapart or remotely located from one another as in the previousembodiment. Further, in alternate embodiments, the internal housing 217may be spaced apart or located remotely from the external housing 219.For example, as shown and labeled an optional internal housing 221 isshown mounted on the interior and/or on the rear wall of the vehicle cab13.

Other locations may be suitable for remote locating, but the rear of thecab 13 provides the conditioned air in a location suitable for coolingthe resting person for example in the sleeper area 19 of the cab 13. Forexample, with reference to FIG. 3B, another embodiment is shown whereinthe housing 216 is defined by an internal housing 217 and an externalhousing 219. In such embodiment, the internal housing 217 is located inthe cab 13, specifically in the rear of the cab 13 wherein closest to anarea where a person might sleep. In this embodiment, the externalhousing 219 is located on a lower exterior area of the vehicle 12. Forexample, in this embodiment, the external housing 219 may be locatedadjacent to the fuel tank or connected to the frame of the vehicle 12.In this embodiment, the internal housing 217 may include an evaporatorcoil, evaporator fan and a controller, for example. The external housing219 may include a compressor, condenser coil and condenser fan, forexample. With reference to FIG. 3C, the external housing 219 is shownmounted in the cab 13 and indicative that the internal housing 217, ifutilized, may be mounted in a plurality of locations as referenced incomparison to FIG. 3A.

According to the instant depicted embodiment of FIG. 3A, the internalhousing 217 may comprise the evaporator 50 (FIG. 7 ) and the printedcircuit board 310 (FIG. 9B) with attached controller 300 (FIG. 9B).Further, the second external housing 219 may include the compressor 40,condenser 44 and condenser fan 45. The fluid connection for refrigerantmay be internally maintained passing through the interface between theinternal and external housing 217, 219.

On any of the depicted embodiments, the air conditioning system 10 mayalso include a display 342 (FIG. 9B) having a distinct printed circuitboard 340 (FIG. 9B) for operation of such. The display 342 may allow fora user interface and include input for user adjusted set point inputssuch as temperature. The inputs may include buttons or may includequasi-buttons defined on a touch screen, for example. Other embodimentsof user input may be used as well. The display 342 will also provide theuser with error messages, for example if there is a low battery level,low refrigerant level or other issue or error condition.

Referring now to FIG. 4 , a perspective view of an exemplary housing isshown. In the previous embodiments, the housings have been shownschematically. The instant housing may be housing 16, 116, or 216 butwill be numbered housing 16 for ease of this description. The housing 16includes a shroud 24 and a base 26. The shroud 24 may have at least onetop surface 28 and at least one sidewall 29. Along one or more of thesurfaces 28, 29 may be vent grills or registers 30 for exchanging heatof the condenser with the atmosphere.

At the front of the housing 16, the housing is curved downwardly fromthe top surface. This aids in aerodynamic performance of the housing 16as well as providing an aesthetically pleasing appearance. Further, asshown in the view, the housing 16 includes two grills 30 on each lateralside, that is either side of the axis shown in broken line. The grills30 are located adjacent to locations of at least one condenser to aid inheat exchange of the refrigerant.

The housing 16 is a single housing meaning all of the coolingmechanicals 11 of the air conditioning system 10 are located therein. Aspreviously indicated, the cooling mechanicals 11 may include at leastone condenser 44. The ability to add more than one condenser increasescooling capacity of the air conditioning system 10. In order to providefor such ability to add additional condensers, the housing 16 or housing119, 216 may be formed symmetrically, for example about the axisextending from front to rear. Thus the grills 30 are located at eachlateral end, symmetrically to allow for one, or for example two,condensers. The housing 16 has cooling mechanicals 11 arranged forsymmetrical configuration if more than one is utilized and therefore thehousing 16, may be formed of a symmetrical shape to receive one or morethan one condenser.

Depending from a lower portion of the base 26 is a duct 32. The duct 32may be in fluid communication with an air distribution assembly withinthe vehicle 12. The duct 32 may be partitioned to separate a first airflow, for example to the evaporator 50 (FIG. 7 ) and a second air flow,for example from the evaporator 50. In other embodiments however,multiple housings may be utilized wherein the evaporator 50 is spacedand remote from the one or more condensers.

Referring now to FIG. 5 , a front view of the housing 16 is shown.Again, the housing 16 is shown as symmetrical about an axis which isshown as a broken vertical line in this embodiment. Thus the housing 16may also be symmetrical about an axis extending into and out of the pageas shown in the FIG. 4 and about the vertical axis of FIG. 5 , alsoshown in broken line. Further, if a dual housing configuration isutilized, the housing having the at least one condenser may have thesymmetrical shape. Still further, the condensers, if two are utilized,may be arranged symmetrically therein. This ability to use one or morecondensers allows the ability to increase capacity of cooling as opposedto the use of a single condenser.

Also, extending from the base 26 is the duct 32 for communication withan air distribution assembly within the vehicle 12. Adjacent to the duct32, a wire 34 and connector 36 are shown. The wire 34 may have power andcontrol conductors in communication with other components, for examplethe display printed circuit board 340 (FIG. 9B) and/or other featuressuch as the condenser fans 45 (FIG. 9A) or a compressor 40. Further, theconnector 36 may be in electrical communication with control(s) whichmay be located on the air distribution assembly.

Referring now to FIG. 6 , a side view of the example housing 16embodiment is shown. The sidewall 29 is shown with a sidewall grill 30to aid in heat exchange from the at least one condenser 44 (FIG. 7 ).The opposite sidewall 29 may be formed in symmetrical fashion as seen inFIG. 4 , for use with an additional condenser if desirable. Additionallyin this view, the duct 32 may also be divided to provide airflow to andthe evaporator 50. For example, the duct 32 may comprise an air intakeregister and air output vent represented respectively by flows 33 a, 33b.

Referring now to FIG. 7 , a perspective view of one embodiment of thecooling mechanicals 11 are shown. According to some aspects, the presentembodiments may be expandable to add additional condensers. Thehousings, for example, 16, 119, 219 wherein the condensers 44 may behoused are formed to accept one condenser or to be capable of acceptingadditional condensers in symmetrical arrangement or configuration. Inthe depicted embodiment, the base 26 is shown in broken line providingan outline of an interior space 26 a and the condenser 44 on one side 26b. On an opposite side 26 c, there is an open area which may receive anadditional condenser to increase cooling capacity.

In the instant embodiment, cooling mechanicals 11 including thecompressor 40 is shown in fluid communication with the at least onecondenser 44. The compressor 40 is driven by a DC brushless motor whichis capable of variable speed operation. The compressor 40 is connectedto the condenser 44 by a fluid conduit 42 which provides fluidcommunication from the compressor 40 to the condenser 44. A secondconduit 47 is in fluid communication between the condenser 44 and anexpansion valve 48. An optional fluid vessel 46, for example aseparator, is shown disposed between the condenser 44 and the expansionvalve 48 and may be used to receive fluid from the condenser 44 and anoptional additional second condenser (not shown) if the second condenseris utilized. The separator 46 is in fluid communication with theexpansion valve 48. The separator 46 may separate gas form of therefrigerant from liquid refrigerant before the fluid refrigerantcontinues to the expansion valve 48.

Extending from the expansion valve 48 is a fluid conduit 49 whichprovides a fluid input to the evaporator 50. The evaporator 50 includesa plurality of coils therein which serpentine and are in flowcommunication with the duct 32 to bring air to the evaporator 50 andpass air over the coils and condition the air so that the conditionedair can pass back into the cabin 13 (FIG. 1 ). Both the condenser 44 andevaporator 50 may include fans to increase heat transfer.

At a second location of the depicted evaporator 50, a second conduit 52extends from the evaporator 50 to return refrigerant from the evaporator50 to the compressor 40. The conduit 52 is shown wrapped in an insulator53 and returns to the compressor 40 to complete the fluid circuit. Theinsulator 53 may be formed of various materials but in some embodimentsis formed of closed cell foam or synthetic rubber, for example CFC orHCFC.

In operation, as described previously, the vapor-compression cycle usesa circulating liquid refrigerant as the medium which absorbs and removesheat from the space to be cooled such as the cabin air and subsequentlyrejects that heat elsewhere for example at the condenser 44. Circulatingrefrigerant enters the compressor 40 in the thermodynamic state known asa saturated vapor and is compressed to a higher pressure furtherresulting in a higher temperature. The hot, compressed refrigerant vaporis then in the thermodynamic state known as a superheated vapor and itis at a temperature and pressure at which it can be condensed witheither cooling water or cooling air. That hot vapor is routed throughthe condenser 44 where it is cooled and condensed into a liquid byflowing through a coil or tubes with air flowing across the coil ortubes. This may be forced air, for example by way of a fan (not shown).In the condenser 44, the circulating refrigerant rejects heat from thesystem and the rejected heat is carried away to atmospheric air. Thecondensed liquid refrigerant, in the thermodynamic state known as asaturated liquid, is next routed through the expansion valve 48 where itundergoes a reduction in pressure. That pressure reduction results inthe adiabatic flash evaporation of a part of the liquid refrigerant. Theauto-refrigeration effect of the adiabatic flash evaporation lowers thetemperature of the liquid and vapor refrigerant mixture to where it iscolder than the temperature of the enclosed space to be refrigerated.The cold mixture is then routed through the coil or tubes in theevaporator 50. A fan 51 (FIG. 9A) circulates the warm air of the vehiclecabin 13 across the evaporator coils or tubes carrying the coldrefrigerant liquid and vapor mixture. That warm air evaporates theliquid part of the cold refrigerant mixture. At the same time, thecirculating air is cooled and thus lowers the temperature of theenclosed space to the desired temperature as such cabin air is returnedthrough the duct 32 (FIG. 5 ). The evaporator 50 is where thecirculating refrigerant absorbs and removes heat which is subsequentlyrejected in the condenser and transferred elsewhere by the water or airused in the condenser 44. To complete the refrigeration cycle, therefrigerant vapor from the evaporator 50 is again a saturated vapor andis routed back into the compressor 40.

Various refrigerant types may be utilized. In some embodiments, R-134Ais utilized as a refrigerant. However this is non-limiting as others maybe used including but not limited to R-11, R-12, HCFCs such as R-22 andHFCs R-134a, which is used in many vehicles. HCFCs are being phased outunder the Montreal Protocol and replaced by hydrofluorocarbons (HFCs),such as R-410A, which lack chlorine. Still further, newer refrigerantsmay include supercritical carbon dioxide, known as R-744. These havesimilar efficiencies compared to existing CFC and HFC based compounds,and have lower global warming potential. These are merely exampleshowever as other refrigerants may be used.

Various types of compressors may be utilized. In some embodiments,reciprocating compressors are used. In some other embodiments, rotaryscrew compressors may be used, or centrifugal compressors, scrollcompressors, diaphragm, or axial flow. In any of these types, it isdesirable that the compressor be driven by a variable speed motor. Insome embodiments, the motor may be a DC brushless variable speed motorso that the speed of the compressor rotation may be varied. According tosome embodiments, the compressor 40 may operate between 1200 RPM and3600 RPM however other speeds, accelerations and ranges may be utilized.

The present embodiments may vary the speed of the compressor 40 in orderto decrease power consumption of the battery and extend battery life.The speed decrease may be related to various factors including but notlimited to a comparison of the set point temperature and the actualtemperature so that as the differential between the two temperaturesdecreases, the compressor power consumption decreases by decreasingspeed of the motor of the compressor 40. In other embodiments however,the temperature differential may be used in combination with otherfactors such as remaining power in the battery or batteries, thepressure of the refrigerant and/or other factors.

Further according to some embodiments, the condenser 44 may be a 1000 Wcondenser including at least one condenser fan, to exchange heat toatmosphere. According to some embodiments, the heat rejection should behigher than the desired cooling capacity. For example, if 1000 W ofcooling is desired, then 1300 W of heat rejection may be required.Further, if desirable, the user or manufacturer may add an additionalcondenser to an open space symmetrically opposed to the first condenser44.

Referring now to FIG. 8 , such further alternative embodiment is shownin perspective view. The present embodiment is shown with an additionalcondenser 144. The second condenser 144 is in fluid communication withcompressor 40 at a Y-fitting 146 which splits the flow of refrigerantbetween the first and second condensers 44, 144. A conduit 148 extendsfrom the fitting 146 to the second condenser 144. After passing throughthe second condenser 144, the refrigerant flow is directed to the vessel46 through conduit 147.

According to this embodiment, the condensers 44, 144 may besubstantially equivalent in capacity or alternatively may differ incapacity. The instant condensers 44, 144 may be of 1000 W capacity for acombined total of 2000 W. As mentioned previously, if 2000 W of coolingis desired, it may be necessary or desirable to reject a higher amountof heat, for example 2600 W. This is desirable for increased coolingcapacity for the refrigerant and thus increasing the cooling capacity ofthe air conditioning system 10 as a whole. Further, the condensers 44,144 are arranged symmetrically so that when placed within a singlehousing or a dual housing portion wherein the condensers are located,the condensers 44, 144 may be arranged in symmetrical fashion about oneor more center lines of the housing. Further, the ability to add thesecond condenser 144 provides some modularity to the air conditioningsystem 10.

Referring now to FIGS. 9A-9B, a schematic view of an embodiment ofvarious components of a parking cooler is shown, including a controller300 mounted or otherwise coupled to a printed circuit board 310,including a microprocessor or microprocessor unit 312. The printedcircuit board 310 may also have an on-board driver 39 for driving themotor of the variable speed compressor 40. The compressor 40 thereforedoes not require a separate on-board driver as is consistent with priorart devices. Further, the compressor 40, with direct connection to theprinted circuit board 310, may limit losses associated with wiring, aswell as distortion of power supply associated with power travel overdistances of wiring. For example, in some embodiments at least a tachoor other feedback wire between the compressor 40 and the printed circuitboard 310 may be omitted by provision of on-board driver 39. In someembodiments, the driver 39 may include, for example, an insulated-gatebipolar transistor (IGBT). For instance, the driver 39 may be a variablefrequency drive that includes an IGBT.

The term “controller” is used herein generally to describe variousapparatus relating to regulation of temperature. A controller can beimplemented in numerous ways (e.g., such as with dedicated hardware) toperform various functions discussed herein. A “processor” is one exampleof a controller which employs one or more microprocessors that may beprogrammed using software (e.g., microcode) to perform various functionsdiscussed herein. A controller may be implemented with or withoutemploying a processor, and also may be implemented as a combination ofdedicated hardware to perform some functions and a processor (e.g., oneor more programmed microprocessors and associated circuitry) to performother functions. Examples of controller components that may be employedin various implementations include, but are not limited to, conventionalmicroprocessors, application specific integrated circuits (ASICs), andfield-programmable gate arrays (FPGAs).

In various embodiments, a processor or controller may be associated withone or more storage media (generically referred to herein as “memory”e.g., volatile and non-volatile computer memory such as RAM, PROM,EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetictape, etc.). In some embodiments, the memory may be encoded with one ormore programs that, when executed by the controller 300, perform atleast some of the functions discussed herein. Memory may be fixed withina processor or controller or may be transportable, such that the one ormore programs stored thereon can be loaded into a processor orcontroller so as to implement various aspects of implementationsdisclosed herein. In some embodiments, the memory may also be mounted orotherwise coupled to the printed circuit board 310.

The printed circuit board 310 also includes a plurality of inputs andoutputs, generally ports 314, 316, 318, 321, 323, for connection toother components associated with or needing control. As shown in FIGS. 7and 8 , the condensers 44, 144 and evaporator 50 are located relative toother components within at least one housing 16 (FIG. 1 ) for example.As shown relative to the controller 300, various actuators are providedfor the parking cooler which provide the proper cooling function. Theactuators are shown within a broken line for purpose of description andcomprise the variable speed compressor 40, as well as fans and a pump,according to some embodiments. The variable speed compressor 40 is shownhaving three conductors indicated as U, V, W each corresponding to onephase of 3-phase DC power to the variable speed compressor 40. At oneend, the three conductors U, V, W are connected to the compressor 40(e.g., directly to the motor of the compressor 40) and at the oppositeend to the printed circuit board 310, and more specifically to phaseoutputs of the on-board driver 39.

The printed circuit board 310 also comprises a converter 54 which maystep up voltage from 12 or 24 Volts to a higher voltage necessary todrive the motor of the variable speed compressor 40. For example, theconverter 54 may step the voltage up to 180V for the three phase drivingby the driver 39. The printed circuit board 310 may also optionallyinclude a DC/DC converter 57. This converter 57 may be used, fornon-limiting example, if the power supply is 12V and needs to be steppedup to a higher voltage, for operating fans of the evaporator and one ormore condensers.

Further, depicted adjacent to the variable speed compressor 40 is anevaporator fan 51. The evaporator fan 51 may include an on-board driver55 which is in communication with the printed circuit board 310 to drivea fan motor for the evaporator 50.

Still further, a condenser fan 45 is also shown on the schematic andincluded with the actuators. As previously described, the at least onecondenser 44 is utilized and allows for expansion within the at leastone housing 16 in order to provide added cooling capacity. The condenserfan 45 is also shown with an on-board driver 43 which is in electricalcommunication with the printed circuit board 310. Similarly, if a secondor more condenser is utilized, a second condenser fan 145 and driver 143may be in communication with the controller 300 and/or printed circuitboard 310.

Each of the evaporator fan driver 55 and the condenser fan driver 43 arein electrical communication with the printed circuit board 310. Each ofthe drivers 55, 43 may have a positive and negative power connection anda speed signal connection 67, 68 which directs the drivers 55, 43 todrive the fans at a desired speed. Further, the drivers 55, 43 mayinclude a feedback signal connection 56, 58 with the printed circuitboard 310. The feedback signal connection 56, 58 may provide, forexample a tachometer signal to the controller 300 to verify fan speeds.

Other optional features may be provided as well. As discussedpreviously, the at least one condenser 44 may be expanded to include asecond condenser and condenser fan in a higher cooling capacityembodiment. Such actuator is depicted.

Still further, the condensate water pump 59 may be desired in the atleast one housing 16 as well. The condensate pump 59 may be used toremove fluid from a housing interior in order to rid the fluid thereinfrom building and creating further problems. The pump 59 may collectfluids located in the base 26 (FIG. 5 ) and pump them exteriorly,depending on the arrangement and orientation of the at least one housing16 and the components therein.

Along the left side of the schematic printed circuit board 310, are aplurality of sensor inputs. Starting at the upper end of the schematicis a compressor temperature sensor 320. The compressor temperaturesensor 320 is used to measure the temperature of the compressor 40 forvarious reasons including, but not limited to, overheat protection. Ifthe temperature exceeds a specific temperature, the variable speedcompressor 40 may be shut down to prevent permanent damage to thecompressor 40. In some embodiments, shutting down the compressor 40 mayinclude ceasing providing of power by on-board driver 39. For example,the controller 300 may determine an overheat condition based on inputfrom compressor temperature sensor 320 and, in response to suchdetection, cause the on-board driver 39 to cease providing power.

Additionally, a cabin temperature sensor 322 is provided. The cabintemperature sensor 322 is shown in electrical communication with theprinted circuit board 310. The cabin temperature sensor 322 is used toprovide the cabin temperature to the controller 300 for use comparingthe set point temperature input by the user, to the cabin (actual)temperature. Based on this comparison, the controller 300 may make adetermination to increase or decrease speed of the compressor 40. Whenthe differential between set point and actual temperature is higher, thecompressor 40 may be run at higher speeds and/or more frequently incycle to effectuate the desired cooling. However, as the differentialdecreases, the compressor speed may be reduced in order to reducebattery power usage and prolong the operation of the air conditioningsystem 10. Further, the increment of change of speed may also be varied.Such change in speed increment may be desirable to reduce the overshootof a set point temperature when approaching such set point temperature.This provides more stable temperature approach and control and lessoscillation above and below the set point temperature.

The controller 300 may also include an outdoor (ambient) temperaturesensor 324. The air conditioning system 10 may have limitations onoperating conditions, such as ambient temperature conditions beingeither too high or too low. The outdoor or ambient temperature sensor324 will provide a temperature signal to the controller 300 from whichthe controller 300 may determine if ambient conditions are appropriatefor operation.

A battery voltage sensor 326 may also be provided. The voltage sensor326 may be directly connected to the one or more batteries so as toobtain an actual voltage level of the one or more batteries, which isnot influenced by other components on the circuit. In other words a truereading may be provided of voltage, uninfluenced by other factors.

A water level indicator 328 may optionally be provided. The water levelindicator 328 may also be utilized to provide a signal to the controller300 in order to drive the optional condensate water pump 59. Thus, ifwater in the at least one housing 16 reaches a certain level, theindicator 328 signals the controller 300 which directs the condensatepump 59 to remove water from the housing 16.

Referring to the opposite side of the printed circuit board 310 is apower supply connection 330. A power supply 332 is shown adjacent to theconnection 330 and may be a power supply from a vehicle battery or maybe a battery pack which is separate of the vehicle starting system. Thepower supply 332 may be a DC power supply and may be a 12V or a 24Vpower supply.

Still further, a display printed circuit board (“PCB”) 340 is shown. Thedisplay PCB 340 in some embodiments is operatively connected to adisplay 344 which may have discrete buttons or may have a touch screenfor input of user commands. The display 344 may be connected to (e.g.,mounted on) the display PCB 340 by wired connection or by wirelessconnection, such as where the display PCB 340 is disposed in a separatehousing for non-limiting example. Such optional or alternativeembodiment is shown as an alternative embodiment as display 342connected by a broken line.

The display printed circuit board 340 may have modules for performingvarious functions. According to some embodiments, the printed circuitboard may have a display module 344 to provide a user display or, in thealternative or additionally, to drive a remotely located display 342.The display module 344 may have a graphics processor as well as adisplay, such as for non-limiting example a liquid crystal display (LCD)or an LED display. Similarly, the remote display 342 if utilized, mayalso be of these or alternative display types. Additionally, the displayprinted circuit board 340 may include a user interface module 346 whichreceives input from buttons or touchscreen on the display 342. Stillfurther, in some embodiments, the display printed circuit board 340 mayinclude a tilt sensor 348. It may be desirable that the tilt sensor 348be calibrated to confirm that the vehicle or at least one housing is notoutside of a predefined angle for safe operation of the air conditioningsystem 10. Thus, the display PCB 340 may manage user input and userinterface with the air conditioning system 10 to provide anaesthetically pleasing interface which is also functionally easy tooperate.

As further shown in the instant embodiment, a bus 350 is shown forcommunication from the display printed circuit board 340 to the mainprinted circuit board 310. The bus 350 may deliver operating parametersfrom the display printed circuit board 340 to the printed circuit board310. Such parameters may include operating mode selection, settemperature, tilt error from the tilt sensor 348, and other parameters.

A line bus interface 374 is shown and allows for operation orcommunication with a bus of the vehicle cooling. For example, where theair conditioning system or parking cooler is to be in communication withthe vehicle integrated cooling system, the interface 374 allows forcommunication with the vehicle cooling system for improved performanceand control. Still further communication one or more communication ports360 may be provided, for example to provide error feedback from the mainprinted circuit board 310 to the display circuit board 340. In the eventof such error detection at the printed circuit board 310, the displaycircuit board 340 may direct an error message on the display 342. Evenfurther, the printed circuit board 310 may provide power to the displayprinted circuit board 340 via power bus 362 or in the alternative mayprovide two-way power signal between the display PCB 340 and the printedcircuit board 310.

Also located on the printed circuit board 310 is an interface 370.Various interface types may be utilized with at least one goal being forupdates of software, firmware or other programming on the printedcircuit board 310. Still further, the interface 370 may also be used fordiagnostic analysis, repair and/or service work. The interface may be ofvarious forms including but not limited to RS-232, USB X.X, RJ-11,RJ-45, Thunderbolt and others.

In further embodiments, the display 342, in combination with the displayprinted circuit board 340, may provide for various operating modes whichmay be selected by a user or may have some or all decisions made by thecontroller 300. In some embodiments, there may be an automatic modewherein operating characteristics are determined based on differentialbetween the set temperature and the cabin temperature. In the automaticmode, the speed of the compressor 40 and fans are regulated based ontemperature differential between the set temperature (user dictated) andthe cabin temperature. As the cabin temperature approaches the settemperature, the incremental change in compressor speed may decrease.Alternatively, the change in compressor speed may be incrementallylarger when the differential between the set point and cabin temperatureis larger. Once the temperature differential is within a preselectedrange, for non-limiting example+ or −1K, the speed of the compressor mayremain unchanged.

Likewise, the temperature differential between set point temperature andcabin temperature may cause larger or smaller increases or decreases inthe fan speeds of evaporator and condenser fans 51, 45. Where there is alarger differential, the fan speed may change by incrementally largeramounts. As the temperature differential becomes smaller, the amount ofincremental change of the fan speed become smaller. The fan speed may bedynamically changing or may change in discrete steps or amounts. Thismay be dependent upon how the change in fan speed, compressor speed orboth affect overall interior noise levels.

In other embodiments, which may be alternative or additional, there maybe an economy mode. In the economy mode, the controller 300 may operatelike the automatic mode but alternatively, may have a maximum compressorspeed which is reduced relative to the automatic mode. For example, theeconomy mode may have a maximum compressor speed of less than the, forexample, 3600 rpm maximum.

In a further alternative mode, a manual mode, the speed of evaporatorfan 51 may be set. For example, the evaporator fan speed may be set insome preselected number of incremental values. There may be a low,medium, and high speed or alternatively, there may be more or fewerpreselected speeds. For example, in some embodiments the system mayutilize five speed settings. Also, for example, in some embodiments thesystem may utilize continuously variable speed settings. Thus, varioussettings are available to provide a desired cooling level to aid inachieving necessary rest.

Still further, the controller 300 may also have a boost mode. This modemay be desirable when fast cooling of the cabin is needed at a maximumperformance level. In such embodiment, the compressor speed and fanspeed are set to maximum values. The boost mode may be set to apreselected (or user selected) time limit, for example 20 minutes orsome other designated time period. Once the time period is reached, thecontroller 300 may revert to manual or automatic mode, for example.Alternatively, when the set temperature is reached, the controller 300may change modes rather than continuing in the boost mode in order toincrease battery usage time.

The system may also comprise a timed or time mode of operation. Thismode may be most beneficial in the automated, manual or economy modes orsettings. The timer mode may provide some preselected time limit foroperation, after which the air conditioner is turned off. Alternatively,the time period may be selected by the user, for example and may beadjusted based on a desired time period of operation. This selection maybe made at the user interface 346 of the display PCB 340.

A further feature of the present embodiments may be under-voltageprotection. The controller 300 includes a battery voltage sensor 326 aspreviously described. If the battery voltage drops below a pre-definedthreshold for some period of time, the air conditioning system may beshut down. The end user may be able to change the threshold level withinthe user interface 346 by way of the display PCB 340 or alternatively,through manufacturer or service representative, programming throughinterface 370. The threshold may be changed, for example between anupper limit and a lower limit. Therefore, a vehicle specific or usagespecific setting may be possible.

A time delay may be necessary to avoid the air conditioning system fromshutting off due to a short load dump. A previously mentioned, aseparate cable may be desirable to ensure an accurate measurement ofvoltage is provided and unaffected by other components or due to voltagedrop or loss in a main cable.

Further, there may be a hysteresis value which should be exceeded beforethe air conditioning system 10 can be restarted. This may preventunstable behavior due to slight voltage increase with the current loadis switched off or removed.

The main printed circuit board 310 of the controller 300 also providesthe additional advantage of being a universal board which may be usedfor different arrangements. As noted previously, various optionalfeatures may be built into the air conditioning system 10, including butnot limited to, a condensate water pump, a water level indicator, and anadditional condenser fan. The controller 300 will operate any of thevarious air conditioning systems readily. Therefore, in manufacturing orin service and repair, the need for differing control systems is needed.Instead, a single controller may be utilized and can make determinationsabout the actuators and sensors utilized in order to determine how toproperly operate the air conditioning system 10. This determination maybe made by way of pre-programming the controller 300, in which case thecontroller 300 is only making a determination of presence of theactuator, or may be made in real-time as a function of the start-upprocess for the controller 300, wherein at each start-up for example,the controller 300 determines which actuators and sensors are presentand determines how to best operate the air conditioning system 10.Alternatively, the controller 300 may determine based on programmingwhether the proper actuators are present to operate properly. Thus insome embodiments, the controller 300 may compare the programming valuesfor actuators which are supposed to be present versus actual values toensure the actuators needed for operation are in fact present. If theactual value doesn't match the programmed value, then an error messagemay be created.

According to some embodiments, the controller 300 may determine if theactuators and sensors which are needed for operation are in factconnected. When the controller 300 is programmed, it may be programmedwith corresponding necessary actuators and/or sensors needed for properoperation. Thus the determination may be made at start up whether thenecessary actuators and sensors are all present by electricalcommunication with the circuit board 310.

In some embodiments, the voltage provided by the one or more batteriesmay be 12V, 24V or may be other voltages. In some embodiments, theprinted circuit board 310 may operate at some standard voltage, forexample 24V. Therefore a DC-DC converter 57 may be provided to step upthe voltage from the one or more batteries from for example 12V to thedesired voltage of 24V, for example.

Once the controller 300 determines that either all of the necessaryactuators are present, or that one or more actuators or sensors are notpresent, the printed circuit board will either make a determination thatoperation can continue or an error message will be sent to the displayprinted circuit board 340.

In the case that operation proceeds, the display circuit board 340 willprovide a further signal to the main printed circuit board 310. Thedisplay printed circuit board 340 will also receive a user inputcorresponding to an operating mode. The operation of the airconditioning system 10 is controlled by control values for theactuators, which correspond to specific mode settings. As discussed, theair conditioning system 10 may operate in a variety of modes. Forexample, the system may function in automatic mode, in economy mode, inmanual mode and in boost mode. The parameter for example, automatic,economy, boost or manual modes may be sent from the display printedcircuit board 340 to the main printed circuit board 310. The parametersignal may be so specific as to include operating speeds or theparameter may be a more general signal which is sent to the main printedcircuit board 310 (e.g., to the controller 300) and the actual speedsignal or control value for the actuators may be stored on the mainprinted circuit board 310 (e.g., in memory associated with thecontroller 300) for direction to the motors. Each of these modes havecorresponding control values for the mode.

Accordingly, the display printed circuit board 340 may provide a signalto the printed circuit board 310 (e.g., to the controller 300) havingthe desired operating mode while the control values are stored on theprinted circuit board 310 (e.g., on memory associated with thecontroller 300). Or, alternatively, the display printed circuit board340 may provide the actual control values to the printed circuit board310. In either embodiment, the control values direct the speeds of thecompressor 40 and fans 51, 45. For example, when the boost mode isselected and maximum cooling is desired, the control values may providethat the compressor 40 may be set to maximum speed and the evaporatorand condenser fans 51, 45 may be set to maximum speed. Further, a timelimit may be sent to the main printed circuit board since the boost modemay be operated at a preselected period of time in order to extendbattery life.

In an economy mode, alternate control values may provide a reducedcompressor speed. Further, the speeds of the evaporator and condenserfans 51, 41 may also be reduced. The settings for economy mode may bestored on the printed circuit board 310 (e.g., in memory associated withthe controller 300) or may be sent from the display printed circuitboard 340 when the mode selection is made.

In the automatic mode, preselected speed setting may be provided eitherfrom the display printed circuit board 340 or may be stored on the mainprinted circuit board 310 (e.g., in memory associated with thecontroller 300) once the display printed circuit board 340 signals whichmode of operation is desired. The motor speed will reduce speed as thedifferential between set temperature and actual temperature decrease.Further, the increment of compressor and/or fan speed change maydecrease as the differential decreases. Alternatively, the incrementalfan and/or compressor speed may increase if the differential is higher.

In the manual mode, the inputs are provided at the display printedcircuit board 340 for example from the display 342. As a result, themanual settings for the actuators may be on the printed circuit board310 (e.g., in memory associated with the controller 300) or may be onthe display printed circuit board 340 and sent to the printed circuitboard 310, as with the other modes.

Referring now to FIG. 10 , a method 1000 of utilizing the automaticoperation mode is shown. Other embodiments may perform the steps ofmethod 1000 in a different order, omit certain steps, and/or performdifferent and/or additional steps than those illustrated. A system ofone or more components (e.g., component(s) of FIGS. 9A and 9B) mayperform the method 1000 such as, for example, controller 300.

In some embodiments, the speed changes of the compressor may be made ata constant acceleration or deceleration. For example, the accelerationor deceleration may be at some preselected increments such as forexample 300 revolutions per minute (RPM) per second or theacceleration/deceleration may vary depending on the situation or modebeing operated. Alternatively, other rates of acceleration may bedesirable or the rate of acceleration may vary. Further, in thisembodiment, the evaporator and condenser fan speed changes may beautomatically regulated. In the method 1000 shown in FIG. 10 , thecompressor and fans are automatically controlled and the display 342will show a predefined automatic mode symbol.

The automatic control method is first discussed. At the beginning of themethod 1000, the variable input set temperature (T_set) is input at step1002. This may be done by the user to input a desired cabin temperature.Next, at step 1004, the system determines if the set temperature (T_set)is not equal to a temperature previously defined by a user (T_set_old).If the values are not equal, the T_set_old is set to the used inputtedT_set at step 1006. If the answer at step 1004 is yes the processcontinues at step 1006. Thus, the input set temperature is used even ifit was previously used. The method 1000 next determines whether thecabin temperature (Tcabin) is less than the set temperature (T_set)minus some preselected variable, such as for non-limiting example, 1K atstep 1008. If the temperature of the cabin (Tcabin) is less than the settemperature (T_set) minus 1K, then the method 1000 next begins acompressor power down step 1014. The compressor speed may be changed ormaintained at a minimum speed or may be turned off. Next the method 1000may determine may be ended at step 1016. It should be understood thatthe method described is a repeating process which occurs multiple timeswithin a given time period. Thus, one skilled in the art will recognizethat the process will return to the top of the method depicted and startagain in a cycle. This method may occur in addition to other processeswhich the controller 300 may be performing simultaneously or serially ina series of methods.

Alternatively, at step 1008, if the cabin temperature (Tcabin) is notless than the set temperature (T_set) minus 1K, a fine regulationprocess may occur at step 1010. Fine regulation relates to fineadjustment of temperature, for example when the actual cabin temperatureis close or within a specific range relative to the set temperature,thus requiring only fine adjustment. Next at step 1012, the method 1000determines if the cabin temperature (Tcabin) is greater than the settemperature (T_set) plus 1K. If the determination is yes, then a finecontrol value is stored and the method 1000 loops back in the process togo through the steps again by way of step 1016. If the temperature ofthe cabin is not greater than the set temperature plus some variable atstep 1012, the process may end at step 1016 and the method cycle again.

Returning again to step 1006, the method 1000 may determine if the cabintemperature is greater than the set temperature at step 1018. If themethod 1000 determines that the cabin temperature is greater than orequal to the set temperature at step 1018, a rough regulation step 1020may occur. Rough regulation refers to temperature regulation oradjustment when the actual cabin temperature is farther from the desiredset temperature, thus requiring a more rough adjustment than thepreviously described fine adjustment. Next, the method 1000 againdetermines if the cabin temperature is equal to the set temperature atstep 1022. If the answer is no at step 1022, the process may end at step1016 and cycle through the process again. If alternatively the answer isyes at step 1022, the method 1000 may store a value and loop back to thebeginning of the method or step intermediate thereto by way of step1016.

During these steps, the compressor speed may be varied in speeddepending on the comparison of the set temperature to the cabintemperature. Further, the fan speeds for the evaporator and condenserfans 51, 45 may be varied or may be maintained as a constant. Forexample, in some embodiments, the evaporator fan 51 may be set to 80% ofmaximum speed and the condenser fan speed may be set at 50%. Thepercentage may be a percentage of maximum operating speed or apercentage of a normal operating speed which may be a differentpreselected value. The amount of increase of compressor speed may bedependent on compressor capacity, motor size and other variables whichmay affect change of temperature by flow rate variations. Similarly, thevalues for the fan speed may be dependent on at least motor type, fantype and size, and flow rates associated with operating ranges.

In the automatic mode, the process may loop to continually compare settemperature and actual temperature and therefore adjust operation. Theentire process may start again for example based on a time limit, uponthe expiration of which the process starts again by comparing the settemperature to a measured cabin temperature, or upon a new input of settemperature. Other basis for starting the process may be utilized aswell. When the cabin temperature reaches the actual temperature, thecompressor may power down after several cycles through the method 1000.For example, a preselected time period may be set within which theactual temperature is stable and at the set temperature or within adesired range. After this preselected time period, the compressor maypower down to a lower speed or be shut down. However it may be that shutdown does not occur for at least several minutes of temperaturestability at or near the set temperature.

The previously described method 1000 may be utilized for automatic modeoperation of the air conditioning system 10. In other embodiments, theparking cooler 10 may be operated in an economy mode. In such mode, aneconomy mode symbol may for example appear on the display 342. Aspreviously described, the economy mode is desirable to conserve batterypower and therefore operates at a reduced cooling capacity for longeroperating time, for example on battery power. In this method, thecompressor speed changes may be carried out with a preselectedacceleration/deceleration amounts or alternative rates or non-constantacceleration as previously described. Further, the evaporator fan speedand the condenser fan speed may automatically be regulated to lowervalues than in the previous automatic mode embodiment.

The economy mode is now described. Various steps are similar to theembodiment of FIG. 10 . First, a variable input set temperature (T_set)is provided by the user. The method next makes the determination ofwhether the set temperature (T_set) is not equal to an older value of aset temperature (T_set_old) as described in the previous embodiment. Theset temperature (T_set) is stored or replaces the previous old settemperature (T_set_old) and the process continues.

Next, the method makes a determination whether the temperature of thecabin (Tcabin) is less than the temperature set (T_set) minus somevariable such as 1K. If the determination is yes, the compressor speedis decreased, stays the same or powers down. The evaporator fan andcondenser fan may be set to some preselected amount to maintaintemperature or powered down as well. Next, the process ends for somedesired time or until the set temperature is changed. As noted before,the end of the process results in a further cycling through the stepsuntil a stable temperature is reached for a period of time, after whichthe compressor may be powered down to a slower speed or shut off.

Alternatively, if the temperature of the cabin (Tcabin) is not less thanthe temperature set (T_set) minus 1K for example, the method may performsome fine regulation of temperature. This may involve increasingcompressor speed or increasing fan speeds or both for some limited timeperiod. After the fine temperature regulation, the method may againcheck if the cabin temperature is greater than the set temperature plussome variable amount, for example 1K. If the cabin temperature is stillhigher than desired, the process may loop back to an earlier step andbegin again. Alternatively, if the cabin temperature is not greater thanthe set temperature plus some variable, the process may be ended andcycle through again.

Alternatively, after the set temperature is stored, if the cabintemperature is greater than or equal to the set temperature, a roughtemperature regulation process may occur. After such process, the cabintemperature is compared again to the set temperature. If thetemperatures are equal, the returns to the step of determining if thecabin temperature is less than the set temperature plus some variableamount. I after the rough regulation step, the cabin temperature is notequal to the set temperature, the process may end and cycle throughagain.

In the economy mode operation, the speed of the compressor may bereduced as compared to the speed in the automatic mode. Further, the fanspeeds may be reduced relative to the automatic mode. However, these maybe adjusted upwardly to decrease the cabin temperature toward the settemperature. However, the maximum operating speeds of the compressor andthe fans may be limited versus the automatic mode in order to reducepower consumption of the system from the battery.

In addition to the automatic and economy modes, the parking cooler mayalso operate in a boost mode wherein the cooling capacity is maximizedfor a limited period of time to reduce temperature more quickly than inother modes. In this mode, the cooling capacity is maximized in order toeffectuate rapid cooling for a limited period of time with the airconditioning system 10. As in previous embodiments, a boost mode symbolmay be displayed on display 342. In this embodiment as the others, thespeed changes may be carried out at some desired acceleration rate orvaried acceleration rates. In this embodiment, for example, the rotationrate of the compressor may have a maximum 3600 RPM which may be fasterthan the previous embodiments however, this value is merely onenon-limiting example. Other speeds may be utilized.

In this mode, the fan speeds and the compressor speed may be set to somehigher values than in the previous modes. Further, the boost modeoperates for a preselected period of time and this time period may beinput by the user or may be some preprogrammed time period which isstored in the controller 300. Thus, the boost mode may operate with theaid of a timer for the system. The boost mode method may cycle throughthe process multiple times as previously described or may work solely ontimer or may work through the method described and in combination withthe timer.

Finally, the parking cooler 10 may be operated manually in addition tothe previously described modes. In some embodiments, the compressor andcondenser fan speeds may be operated similarly to the method shown inFIG. 10 . Further, in some embodiments, the compressor speed may be keptconstant and only the evaporator fan speed adjusted manually. In otherembodiments, the method involves various speed changes of the compressor40 which may be carried out at some preselected amount, for non-limitingexample, 300 RPM increments. Or, combinations of these manners ofoperation may be utilized. Further, the fan speed of, for example theevaporator fan 51, may be varied manually at some preselected number ofdiscreet values, for example ranging from three speed selections or, inother embodiments, having more, such as for example five speedselections. The amount of control may be varied by varying the number ofsteps involved in evaporator fan speed operation.

The user defined set temperature (T_set) and a speed set correspondingto some predefined speed setting for the evaporator fan, for examplelow, medium or high. It may be desirable for simplicity to use somepreselected condenser fan speed in the manual operation mode, althoughin some embodiments the condenser fan speed may also be adjusted basedon temperature differences between the set temperature and the cabintemperature. The speeds may be adjusted downwardly by the controller 300when the desired temperature is reached, again in an effort to reducepower consumption of the battery.

While several inventive embodiments have been described and illustratedherein, those of ordinary skill in the art will readily envision avariety of other means and/or structures for performing the functionand/or obtaining the results and/or one or more of the advantagesdescribed herein, and each of such variations and/or modifications isdeemed to be within the scope of the invent of embodiments describedherein. More generally, those skilled in the art will readily appreciatethat all parameters, dimensions, materials, and configurations describedherein are meant to be exemplary and that the actual parameters,dimensions, materials, and/or configurations will depend upon thespecific application or applications for which the inventive teaching(s)is/are used. Those skilled in the art will recognize, or be able toascertain using no more than routine experimentation, many equivalentsto the specific inventive embodiments described herein. It is,therefore, to be understood that the foregoing embodiments are presentedby way of example only and that, within the scope of the appended claimsand equivalents thereto, inventive embodiments may be practicedotherwise than as specifically described and claimed. Inventiveembodiments of the present disclosure are directed to each individualfeature, system, article, material, kit, and/or method described herein.In addition, any combination of two or more such features, systems,articles, materials, kits, and/or methods, if such features, systems,articles, materials, kits, and/or methods are not mutually inconsistent,is included within the inventive scope of the present disclosure.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms. The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.” The phrase“and/or,” as used herein in the specification and in the claims, shouldbe understood to mean “either or both” of the elements so conjoined,i.e., elements that are conjunctively present in some cases anddisjunctively present in other cases.

Multiple elements listed with “and/or” should be construed in the samefashion, i.e., “one or more” of the elements so conjoined. Otherelements may optionally be present other than the elements specificallyidentified by the “and/or” clause, whether related or unrelated to thoseelements specifically identified. Thus, as a non-limiting example, areference to “A and/or B”, when used in conjunction with open-endedlanguage such as “comprising” can refer, in one embodiment, to A only(optionally including elements other than B); in another embodiment, toB only (optionally including elements other than A); in yet anotherembodiment, to both A and B (optionally including other elements); etc.

As used herein in the specification and in the claims, “or” should beunderstood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the claims, “consisting of,” will refer to the inclusion of exactlyone element of a number or list of elements. In general, the term “or”as used herein shall only be interpreted as indicating exclusivealternatives (i.e. “one or the other but not both”) when preceded byterms of exclusivity, such as “either,” “one of,” “only one of,” or“exactly one of.” “Consisting essentially of,” when used in the claims,shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

It should also be understood that, unless clearly indicated to thecontrary, in any methods claimed herein that include more than one stepor act, the order of the steps or acts of the method is not necessarilylimited to the order in which the steps or acts of the method arerecited.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively.

The foregoing description of several methods and an embodiment of theinvention has been presented for purposes of illustration. It is notintended to be exhaustive or to limit the invention to the precise stepsand/or forms disclosed, and obviously many modifications and variationsare possible in light of the above teaching. It is intended that thescope of the invention and all equivalents be defined by the claimsappended hereto.

The invention claimed is:
 1. A mobile air conditioning system,comprising: cooling mechanicals including at least a variable speedcompressor having a DC brushless motor, an expansion valve, anevaporator, and at least one condenser; a single housing having a baseand a shroud which form an interior space for positioning of coolingmechanicals; said single housing being configured to house a first oneof said at least one condenser arranged at one side of the interiorspace of the single housing, with additional space set aside within theinterior space of the single housing to house an additional one of saidat least one condenser on a symmetrically opposite side of said interiorspace such that the additional one of said at least one condenser can beprovided within the single housing to increase cooling capacity of themobile air conditioning system.
 2. A mobile air conditioning system,comprising: a single housing having an interior space to house aplurality of cooling mechanicals including a DC brushless variable speedmotor which powers a compressor, an expansion valve, an evaporator andat least one condenser; a printed circuit board disposed within saidsingle housing, said printed circuit board including a microprocessorunit and an on-board driver which drives said DC brushless variablespeed motor to operate said compressor; said on-board driver inelectrical communication with said variable speed compressor having saidDC brushless motor; said printed circuit board also in electricalcommunication with an evaporator fan and at least one condenser fan;and, at least one cabin temperature sensor and an outside temperaturesensor in communication with said printed circuit board; a first one ofsaid at least one condenser arranged at one side of said interior spaceof the single housing, with additional space set aside within theinterior space of the single housing to house a second condenser of saidat least one condenser on a symmetrically opposite side of said interiorspace such that said second condenser of said at least one condenser iscapable of being added within the single housing to increase coolingcapacity of the mobile air conditioning system.
 3. The mobile airconditioning system of claim 2, said printed circuit board incommunication with a remotely positioned display.
 4. The mobile airconditioning system of claim 2, said printed circuit board receivingpower from a vehicle.
 5. The mobile air conditioning system of claim 2,said printed circuit board providing a speed signal to said evaporatorfan and said at least one condenser fan.
 6. The mobile air conditioningsystem of claim 5, said printed circuit board receiving a tachometerfeedback signal.
 7. The mobile air conditioning system of claim 2further comprising at least one communication port on said printedcircuit board for communication with said at least one condenser fan. 8.The mobile air conditioning system of claim 7 further comprising saidsecond condenser in said additional space and a second condenser fan. 9.The mobile air conditioning system of claim 8 said at least onecommunication port also in communication with said second condenser fan.10. The mobile air conditioning system of claim 8, said second condenserand said at least one condenser being symmetrically arranged within saidsingle housing.
 11. The mobile air conditioning system of claim 2further comprising a compressor temperature sensor in communication withsaid printed circuit board.